DNA is short for Deoxyribonucleic (dee-ock-see-rie-boe-nooh-clay-ick) Acid. These microscopic strands are responsible for every detail of how your body looks and functions. DNA is a double strand that looks like a spiral staircase. It is composed of four different proteins. The protiens are paired together and make the "steps" of the staircase. These proteins are Adenine, Guanine, Cytosine, and Thymine. Just the first letter of each protein is used to identify them: A, G, C, or T. Each protein has only one pair. A only pairs with T, and G only pairs with C. These pairs are strung along the DNA strand in almost every possible way.
DNA is located only in the nucleus of your cells. It controls the cells by sending commands to the organelles. These commands are in the form of RNA (ribonucleic acid). RNA is like DNA except for it is only a single strand, instead of the double strand of DNA. It is a half-staircase. RNA strands take molds of one side of DNA molecules and carry this information to the ribosomes to stimulate protein formation. Almost every part of your body is made mainly of different kinds of proteins. Proteins decide what jobs are done.
Millions of DNA molecules are at work to control one function or area of your body. Groups of DNA molecules that are specialized are called genes. Thousands of these genes are on each chromosome, contained in the nucleus of every cell in your body. As cells divide, they become specialized. It is not known how cells determine what kind they are to be, but they only use part of the DNA to form the intended body part.